In this mini lecture series I will discuss some exciting recent developments regarding transverse momentum
dependent factorization theorems and in particular I will focus on the evolution of the parton
densities that appear in these theorems. I will go through some of the explicit next-to-leading order (NLO) calculations
as well as some technical points in the implementation of NLO evolution for the unpolarized TMD correlation functions.
If time permits I will also discuss some recent developments on the evolution of polarized TMDs, in particular the Sivers
function.